primary fluid Q

i was planing on running ATF in my 89 primary,& was told to run type F but not dexron III but when i looked at the bottles marked ATF they said that they were made for dexron-mercon cars so can i use this stuff or just type F ???

I have seen this question several times and my thought has always been that there is more going on the the primary case than just clutch friction. The primary chain and drive gears have to enter into the equasion. I for one will continue to run the lubricants that might be a trade off but have given me good service.

Are you running a stock clutch or an aftermarket? I have a Rivera Primo Pro Clutch in the Fatboy. Their instructions specify Dexron III. But as stated earlier, there are other factors to be put into the equation. I've known people with the same clutch that are running Formula+ with no problems. It's a trade-off in friction modifiers, lubrication and cooling. The primary fluid also dissipates the heat from the stator. If you're running the bike on the strip or riding it like you stole it........TYPE F is it.

In regards to the primary oil, we do not recommend using the HD Formula Plus (the regular old HD primary oil is fine). Any of the aftermarket brands such as Motul, Drag Specialties, Redline, etc. are all fine to use. ATF (Type F) is also ok- B&M Trick Shift has been used for many years with good results as well. If you go with Mobil 1, just make sure it is their oil designed for use in the HD primary (not automotive). The main thing is to just keep good light weight, clean oil in it so it can do it's job to help cool the plates.

In regards to the primary oil, we do not recommend using the HD Formula Plus (the regular old HD primary oil is fine). Any of the aftermarket brands such as Motul, Drag Specialties, Redline, etc. are all fine to use. ATF (Type F) is also ok- B&M Trick Shift has been used for many years with good results as well. If you go with Mobil 1, just make sure it is their oil designed for use in the HD primary (not automotive). The main thing is to just keep good light weight, clean oil in it so it can do it's job to help cool the plates.